The .45 ACP (11.43×23mm) (Automatic Colt Pistol), also known as the .45 Auto by C.I.P., is a cartridge designed by John Browning in 1904, for use in his prototype Colt semi-automatic .45 pistol and eventually the M1911 pistol adopted by the United States Army in 1911.
Read more about .45 ACP: Design and History, Cartridge Dimensions, Performance, Load Variants, Timeline, Synonyms, Related Rounds